3d mode selection mechanism for video playback

ABSTRACT

The invention relates to a signal comprising video information and associated playback information, the video information and associated playback information being organized according to a playback format, the video information comprising a primary video stream for two-dimensional (2D) display, and an additional information stream for enabling three-dimensional (3D) display, wherein that the associated playback information comprises display information indicating the types of display possible. The invention also relates to a method and device for playback of such a signal, the method comprising receiving the video information and the associated playback information, processing the display information to determine that both two-dimensional (2D) display possible and three-dimensional (3D) display are possible for the received video information; determining a playback setting of a playback device indicating whether the video information should be displayed two-dimensional (2D) or three dimensional (3D); and processing for display either the primary video stream or the primary video stream and the additional information stream, in accordance with the playback setting of the playback device.

This application claims the benefit or priority of and describes therelationships between the following applications: wherein thisapplication is a continuation of U.S. patent application Ser. No.12/746,951, filed Jun. 9, 2010, which is the National Stage ofInternational Application No. PCT/IB2008/055185, filed Dec. 10, 2008,which claims the priority of foreign application EPO 07123190 filed Dec.14, 2007, all of which are incorporated herein in whole by reference.

FIELD OF THE INVENTION

The present invention relates to a method of playback of videoinformation suitable for both two-dimensional (2D) display andthree-dimensional (3D) display. This invention also relates to aplayback device for playback of video information suitable for bothtwo-dimensional (2D) display and three-dimensional (3D) display. Thisinvention also relates to a signal comprising video information andassociated playback information and a record carrier comprising recordedthereon a signal.

BACKGROUND OF THE INVENTION

With the introduction of new 3D displays, there is an opportunity for 3Dvideo to break through to the mass consumer market. Such 3D displays areable to handle both 3D display and 2D display. Various formats for 3Dvideo exists today and most are based on single viewpoint stereo,whereby the user can see a scene in stereo from a single viewpoint.However, introducing 3D video does not only relate to introducing newdisplays capable of 3D display, but it also has impact on the wholecontent production and delivery chain. Firstly, the production of 3Dvideo content is at an embryonic technology stage and various formatsare proposed to be used each with their own advantages anddisadvantages. With respect to content distribution, new coding methodswere introduced for coding 3D content and new formats were proposed toinclude the 3D video stream in MPEG streams.

A known fact is that introduction of new formats is usually slow and adesired feature when introducing new format is backwards playbackcompatibility with the installed player base. A missing area has beenthe carriage of 3D video content in a content distribution or publishingformat such as Digital Video Broadcasting (DVB) or DVD and highdefinition format such as Blu-ray Disc (BD) or HD-DVD while maintainingbackwards compatibility with the installed player base. Moreover, 3Ddisplays are only able to create a high quality 3D feeling in a fewspatial regions, compared to the standard 2D image that can be view fromall angular direction. Hence, depending either on the viewing conditionsor on the number of users viewing the display simultaneously or on userpreference, it may be desirable to be able to easily switch 2D and 3Dcontent.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a method of playback ofvideo information suitable for both 2D and 3D display, wherein it iseasy to switch between 2D and 3D content, while maintaining thebackwards compatibility with 2D legacy devices. In the method accordingto the invention, the video information and associated playbackinformation are organized according to a playback format, the videoinformation comprises a primary video stream for two-dimensional (2D)display and an additional information stream for enablingthree-dimensional (3D) display, the associated playback informationcomprises display information indicating the types of video streamspresent; the method comprises receiving the video information and theassociated playback information, processing the display information todetermine that both two-dimensional (2D) display possible andthree-dimensional (3D) display are possible for the received videoinformation; determining a playback setting of a playback deviceindicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D); processing for displayeither the primary video stream or the primary video stream and theadditional information stream, in accordance with the playback settingof the playback device. When the video information comprises a primaryvideo stream for two-dimensional (2D) display and an additionalinformation stream for enabling three-dimensional (3D) display, theadditional information stream is ignored by legacy devices, hence thebackward compatibility is maintained. By processing either the primaryvideo stream for 2D display or both the primary video stream and theauxiliary stream for 3D display in dependence on a detected playbacksetting of a playback device indicating whether the video informationshould be displayed two-dimensional (2D) or three dimensional (3D), theswitch between 2D and 3D content can be easily performed by controllingthe playback setting of the playback device.

When transitioning from 2D to 3D and vice-versa the playback device andthe video processing unit is re-configured to change from onepresentation mode to the other. During this re-configuration processblack frames or artifacts may appear on screen, which severally disruptthe movie experience. To avoid discomfort to the user, in an embodimentof the invention, a duration of the switching from 2D to 3D andvice-versa is controlled in a seamless manner.

To allow the strength of the 3D effect to increase gradually withoutshowing artefacts or black frames requires that the playback device andthe processing stage in the display work together to achieve a“seamless” transition. In an advantageous further embodiment, theswitching takes place only at predefined moments during playback. Forexample, such moments correspond to moment when the content itself issuitable to switch between 2D and 3D, for example at a scene cut, at thebeginning of a new shot. Also the transition may occur in part of thecontent and story line for which it makes sense to switch to a moreimmersive experience for example action shots, or in a part of thecontent where the user can “explore” a scene in more detail. Theseamless transition may be achieved by controlling the 3D depth duringthe transition continuously from zero to a desired value over a periodof time, or vice-versa during 3D-2D transitions. Hence the strength ofthe 3D effect is increased gradually, allowing the users eyes and visualsystem to adjust and become comfortable with the 3D viewing experience.

In an embodiment of the method according to the invention, each streamcomprises items, the associated playback information comprisingplaylists, each playlist indicating a sequence of items to be playedback, at least one playlist comprising a main presentation pathindicating a main sequence of video items of the primary video stream tobe played back and an auxiliary presentation path indicating anauxiliary sequence to be played back, the auxiliary sequence comprisingvideo items from the primary video stream and corresponding informationitems from the additional information stream. This embodiment carriesthe advantage the switch between 2D and 3D content can be obtained byswitching between the main presentation path to the auxiliarypresentation path, and it is suitable to be used when the playbackformat substantially corresponds to Blu-ray playback format.

In another embodiment of the method according to the invention, theplayback format substantially corresponds to DVD-Video playback format,the playback information comprising Video Title Set Information (VTSI)comprising Video Attribute information, characterized by the VideoAttribute information comprising a video attribute indicating that thecorresponding Video Title Set Information (VTSI) comprises theadditional information stream for enabling three-dimensional (3D)display. This enables distribution of 3D video content in the DVD-Videoplayback format by providing information that 3D content is available,while maintaining playback compatibility with legacy DVD player.

Advantageously, the primary video stream and the additional informationstream are MPEG elementary streams multiplexed together in a multiplexedvideo stream, the additional information stream being defined as anauxiliary stream. Auxiliary streams are ignored by a player unlessspecific command to decode the auxiliary stream is received; hencebackwards playback compatibility is obtained.

Furthermore, a successful introduction of 3D video in the consumermarket requires more than good displays, it also requires that 3D videoprovides a new compelling experience to the consumer. In the initialstage of the introduction, it is expected that content authors willexperiment with the new medium whereby parts of a video stream will be3D-video, whilst the main video will still be viewed mostly in 2D or inan enhanced 2D experience, whereby the content is in 2D but it isconverted real-time in the display from 2D to “3D”. Hence, it is notonly desirable to easily switch between 2D and 3D content, but thisswitch from 2D to 3D during presentation should take place in a“seamless” manner. The user end will notice that the presentation haschanged, however the transition should be un-obtrusive, not cause blackframes or other artifacts in the video, which would interfere with thepositive experience of the end-user.

This application also relates to a playback device for playback of videoinformation comprising means for receiving video information andassociated playback information being organized according to a playbackformat, the video information comprising a primary video stream fortwo-dimensional (2D) display and an additional information stream forenabling three-dimensional (3D) display, the associated playbackinformation comprising display information indicating the types of videostreams present; means for processing the display information todetermine that both two-dimensional (2D) display possible andthree-dimensional (3D) display are possible for the received videoinformation; means for storing a playback setting of a playback deviceindicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D); and means for processingfor display either the primary video stream or the primary video streamand the additional information stream, in accordance with the storedplayback setting of the playback device.

This application also relates to a signal and a record carriercomprising recorded thereon said signal, the signal comprising videoinformation and associated playback information the video informationand associated playback information being organized according to aplayback format, the video information comprising primary videoinformation for two-dimensional (2D) display, and additional videoinformation for enabling three-dimensional (3D) display, wherein theassociated playback information comprises display information indicatingthe types of display possible.

These and other aspects of the invention are apparent from and will beexplained with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will be further explainedupon reference to the following drawings, in which:

FIG. 1 illustrates schematically an optical disc;

FIG. 2 illustrates schematically a playback device wherein the inventionis practiced;

FIG. 3. illustrates schematically playback, rendering and display of 3Dcontent on an autostereoscopic multiview display

FIG. 4. illustrate the use of gain and offset parameters in anautostereoscopic display for generating a 2D-3D transition

FIGS. 5A, 5B, 5C and 5D illustrate the use of luma keying foroverlaying“depth” data over 2D image in an interleaved manner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates schematically an optical disc 11 having a track 12and a central hole 10. The track 12, being the position of the series ofpre-recorded marks representing information, is arranged in accordancewith a single spiral pattern constituting substantially parallel trackson an information layer. The optical disc may comprise one or moreinformation layers of a recordable type. Known examples of pre-recordedoptical discs are CD-ROM, or DVD-ROM or high density disc such as HDDVD-ROM or BD-ROM. For example, further details about the physicalstructure and addressing information for CD-ROM and DVD-ROM opticaldiscs can be found in references ECMA-130 and ECMA-267 (ISO IEC 16449),respectively. In case of BD system, further details can be found in thepublicly available technical white papers “Blu-ray Disc Format GeneralAugust 2004” and “Blu-ray Disc 1. C Physical Format Specifications forBD-ROM November, 2005”, published by the Blu-Ray Disc association(http://www.bluraydisc.com). The information is represented on theinformation layer by optically detectable marks along the track. Thetrack 12 on the optical disc is indicated by a pre-embossed trackstructure provided during manufacture of the blank optical disc. Thetrack structure is constituted, for example, by a pregroove, whichenables a read/write head to follow the track during scanning forreading and/or writing.

The optical disc 11 is intended for carrying user information accordingto a standardized format, to be playable on standardized playbackdevices. The recording format includes the way information is recorded,encoded and logically mapped onto the recording space provided by thetrack 12. The recordable space is usually subdivided into a lead-in area(LI) 31, a data zone (DZ) for recording the information and a lead-outarea (LO) 32. The lead-in area (LI) 31 usually comprises basic discmanagement information and information how to physically access the datazone (DZ). For example, said basic disc management informationcorresponds to the table of contents in CD systems or the formattingdisc control blocks (FDCB) in DVD systems.

The user information recorded in the data zone (DZ) is further arrangedaccording to an application format, for example comprising a predefinedstructure of files and directories. Further, at logical level, the userinformation recorded in the data zone is arranged according to a filesystem comprising file management information, such as ISO 9660 used inCD systems, available as ECMA-119, or UDF used in DVD systems, availableas ECMA-167.

FIG. 2 illustrates schematically a recording device and/or aplaybackdevice wherein the invention is practiced.

The recording and/or playback device is provided with scanning means forscanning the track of the optical disc, the scanning means comprising adrive unit 16 for rotating the optical disc 11, a head 18, a positioningunit 21 for coarsely positioning the head 18 in the radial direction onthe track, and a control unit 17. The head 18 comprises an opticalsystem of a known type for generating a radiation beam 20 guided throughoptical elements for focusing said radiation beam 20 to a radiation spot19 on the track 12 of the optical disc 11. The radiation beam 20 isgenerated by a radiation source, e.g. a laser diode. The head furthercomprises (not shown) a focusing actuator for moving the focus of theradiation beam 20 along the optical axis of said beam and a trackingactuator for fine positioning of the radiation spot 19 in a radialdirection on the center of the track. The tracking actuator may comprisecoils for radially moving an optical element or may alternatively bearranged for changing the angle of a reflecting element.

For reading information, the radiation reflected by the informationlayer is detected by a detector of a usual type, e.g. a four-quadrantdiode, in the head 18 for generating a read signal and further detectorsignals, such as a tracking error and a focusing error signal forcontrolling said tracking and focusing actuators. The control unit 17controls the retrieving of information from the optical disc 11, and maybe arranged for receiving commands from a user or from a host computer.To this end, the control unit 17 may comprise control circuitry, forexample a microprocessor, a program memory and control gates, forperforming the procedures described hereinafter. The control unit 17 mayalso be implemented as a state machine in logic circuits.

For reading, the read signal is processed by a read processing unitcomprising a demodulator 26, a de-formatter 27 and output unit 28 forprocessing the information and outputting said information to suitablemeans, such as display, speakers. The functioning of the demodulator 26,the de-formatter 27 and the output unit 28 are controlled by thecontroller 17. Hence, retrieving means for reading information includethe drive unit 16, the head 18, the positioning unit 21 and the readprocessing unit. The demodulator 26 is responsible for de-modulating adata signal from the channel signal, by using suitable channel decoder,e.g. as disclosed in U.S. Pat. No. 5,920,272 or U.S. Pat. No. 5,477,222.The de-formattter 27 is responsible for using error correction codesand/or de-interleaving for extracting the information signal from thedata signal. The output unit 28, under the control of the control unit17, is responsible for processing the information signal at logicallevel. Furthermore, it is noted that the information signal may bearranged according to a playback format, which may prescribe thatmanagement information is associated to the audio-video information.Hence the output unit is responsible for separating managementinformation from the audio-video information, and for de-multiplexingand/or decoding the audio and/or video information. Suitablecompression/de-compression means are described for audio in WO98/16014-A1 (PHN 16452), and for video in the MPEG2 standard (ISO-IEC13818). The recording format in which this the user information is to berecorded prescribes that management information for managing therecorded user information is also recorded onto the optical disc

The video and audio information generated by the output unit 28 is sentto suitable means, such as a suitable display for the video information.A number of auto-stereoscopic devices that are able to switch between 2Dand 3 D displays are known, one of them being described in U.S. Pat. No.6,069,650. The display device comprises an LCD display comprisingactively switchable Liquid Crystal lenticular lens. Depending on theimage content a defined set of locations at the display can be switchedto either 2D or 3D mode. For content providers that intend to make useof such display systems, such as movie studios, it is desirable to beable to distribute both 2D and 3D content on the same record medium in aformat that is playback compatible with legacy players, that players notenabled to display 3D stream should be able to handle the record medium.

FIG. 3 illustrates schematically playback, rendering and display of 3Dcontent on an autostereoscopic multiview display. In auto-stereoscopicdisplays processing inside a processing unit 31 converts the image+depthinput format, outputted by the playback device 20 described withreference to FIG. 2, to multiple views and maps these onto thesub-pixels of the display panel 35. It is duly noted that the processingunit 31, also known as a rendering unit, may reside either inside thedisplay 35 or in the playback device 20. This processing unit 31 dealswith converting the output format of the playback device 20 to a formatsuitable for processing, then generating the required number of views inthe processing unit 31 and then mapping these views onto the rightpixels on the display. The processing unit 31 may suitable comprise ademultiplexer 32 for demultiplexing the outputted stream, a imageprocessing and rendering stage 33 for generating the multiple views andan interweaving unit 34.

With respect to the coding of video information, the multiple viewsnecessary for a 3D display can be computed based on a 2D picture and anadditional picture, a so-called depth map, as described in OliverSheer—“3D Video Communication”, Wiley, 2005, pages 29-34. The depth mapconveys information about the depth of objects in the 2D image. The greyscale values in the depth map indicate the depth of the associated pixelin the 2D image. A stereo display can calculate the additional viewrequired for stereo by using the depth value from the depth map and bycalculating the required pixel transformation. A writing devicecompresses and transmits the 2D picture and depth map. With respect to aformat for compressing and transmitting 3D video information, a solutionis to make use of MPEG streams, wherein an MPEG 3D video stream wouldcomprise a 2D video stream (as either a one program—or a elementaryvideo transport stream) and, multiplexed with the 2D video stream, anauxiliary stream comprising additional information to enable 3D display(such as a depth map stream).

It is noted that although in the above 2D video+depth map was describedas the preferred format for these devices, it is not the only formatthat can be supported. For example the 2D video+depth map may beextended by adding occlusion and transparency information, orstereo+depth may be used as input format. Alternatively the multipleviews may be used as input signal and mapped directly onto the display(sub) pixels.

Furthermore, it may be expected that part of the content is intended for3D display and part of the content is intended for 2D display. Dependingeither on the viewing conditions or on the number of users viewing thedisplay simultaneously or on user preference, it may be desirable to beable to easily switch between 2D and 3D content.

Based on the above considerations, the inventors had the insight that amethod is needed such that the end user, through use of the system, canindicate whether he wishes to play the movie in 2D or 3D mode. In orderfor such method to be implemented the following are required

the player should be able to store a playback setting of a playbackdevice indicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D);

a method or application interface is required that allows thedetermination of the playback setting of the playback device;

the player should be provided with means to process the videoinformation according to the determined playback settings.

With respect to the playback setting, for example, a register may bedefined to store the correct display mode. Additionally, the player maybe provided with a method of accessing the register for reading andwriting the correct value to indicate playback in 2D or 3D mode. Withrespect to the determination of the playback setting, an ApplicationProgrammer Interface (API) may allow an application on the disc to querythe register to determine the default setting of the player (i.e. 3D or2D). Additionally, it may be advantageous, that a further ApplicationProgrammer Interface and a related Call-back method are defined suchthat an application may receive notification of when the value of thisregister changes.

Additionally, it is desirable that the playback device is enabled todetermine which stream (or sub-stream) to select for playback in 3Dmode. This method is similar to a language or audio stream selection,during playback the playback device can select playback of a separatestream that corresponds to a user action. When using a 3D MPEG video asdescribed above (multiplexed 2D video as primary video stream and 3Dinformation encoded as an auxiliary stream), it is necessary that theauxiliary stream that carries the additional 3D information is providedwith a new identifier that indicates the type of the auxiliary stream(i.e. a 3D depth map data). The solution according to the inventors isto include identification of a 3D stream in the metadata definitions ofthe distribution format such that the playback device can select whichtitle contains such an additional auxiliary stream containing 3Dinformation without having to analyze the lower level MPEG systeminformation. Additionally a playback device can use this information toprepare the system in the correct configuration of 3D playback.

Herein below, an embodiment of the invention will be detailed in theparticular case that the playback format substantially corresponds toDVD-Video playback format.

It is known in the art that a playback device enabled to playbackDVD-Video information is provided with several predefined PlayerConfiguration settings, which are used to determine playback setting foraudio (e.g. selection of audio decoder) and video. With respect tovideo, these include a Player Configuration for Video setting (P_CFG)which allows the user to indicate the display mode and the aspect ratio.According to this embodiment of the invention, the Player Configurationfor Video setting is modified. The known Player Configuration for Videosetting is a 4 byte register, from which only the first 4 bits (leastsignificant bits) of the second byte are used for defining the videosettings. According to the invention, the 4 most significant bits of thesecond byte are used to indicate the Display Mode (being either, 3Dmultiview, stereo or 2D etc.) A example of a possible definition ofthese bits:

0000=2D,

0001=stereo,0010=3D multiview.

Furthermore, according to this embodiment of the invention, the knownmethod Video_Presentation_Mode_Change (Mode) is adapted that it furtherallows to change the setting of the Video setting (P_CFG) to any of thevalues as indicated hereinabove.

According to an alternative embodiment of the invention, a new SystemParameter (SPRM) may be added to indicate the player configuration for3D. It is noted that there are two reserved values for system parametersin known DVD players that could be used for this purpose, correspondingto 2D and 3D display. Alternatively, new system parameters could bedefined.

Furthermore, in DVD systems, the concept of navigation is used todescribe the information required by the player to select which streamsto decode and playback according to playback of a certain title. Theinformation that describes attributes of the video streams in a titleare described in the Video Title Set Information (VTSI). in The VideoTitle Set Information (VTSI) comprises a table called the Video TitleSet Information Management Table (VTSI_MAT). This table lists a numberof entries such as the number of audio streams and attributes of thoseaudio streams. It also has entries for sub-pictures streams. It alsocomprises a single video attribute entry (VTS_V_ATR), as in DVD systemsuse only MPEG Program stream, only one video stream being allowed in aProgram Stream. This video attribute entry (VTS_V_ATR) describes whatcompression is used, the aspect ratio, TV system etc. According to thisembodiment of the invention, the video attribute entry (VTS_V_ATR) isextended to further comprise an additional field indicating that thetitle contains 3D information. This extension allows a playback deviceto determine which title comprises 3D information is to extend.

There are several options for implementing such extension. In moredetail, the video attribute entry (VTS_V_ATR) consists of a two byteword, of which the second least significant bit is a reserved bit whichis not used. This can be used to indicate the presence of 3D informationwhereby 0b would indicate no 3D, and 1b would indicate that 3Dinformation is present. Other fields could be used to indicate this,such as the Display Mode field, which has a reserved entry that could beused for this purpose. The use of reserved fields allows a solution thatis compatible with legacy playback devices that are not 3D aware.Furthermore, this provides compatibility with storing the 3D videoinformation in a auxiliary stream, as legacy playback devices ignorethis additional stream. When content is distributed in the formatdescribed above, with 3D information encoded as an auxiliary stream, aplayback device according to the invention is able to determine whichtitle comprises 3D information and, within that title to use theauxiliary stream for providing 3D display.

Herein below, an embodiment of the invention will be detailed in theparticular case that the playback format substantially corresponds to BDplayback format.

BD playback devices use setting registers for storing playbackpreferences, such as user audio language preferences. According to anembodiment of the invention, these registers are extended to include aregister for storing the 3D setting in the playback device such that anapplication on the disc can determine whether to play a title in 2D orin 3D. A preferred embodiment is to include a register and make use ofthe reserved values for the register number. For example Player SettingsRegister (PSR) numbered 20 through 28 are presently reserved and couldbe used for a new register indicating whether the playback device is setto 3D video playback mode or not. Another option is to use reserved bitsin an existing register such as PSR 29 that holds the Player Capabilityfor video. This register currently only uses 2 bits of the reserved fourbytes.

It is noted that, in BD systems, Java application can be used forcontrol of playback. Hence an BD-Java application provided on therecording medium can be executed by the playback device and access thevalue of the playback device settings registers either through the knowgetPSR( )methods or through the known BD user setting and preferenceApplication Interfaces (API's). A Movie mode application can use lowlevel commands to copy the value from a settings register to a generalpurpose register on which it can perform operations such as bit maskingto obtain the status of the players 3D mode.

With respect to navigation and presentation, in BD systems, the conceptof playlists and playitems is used to carry information on presentationof the audio and video content. Playitems are parts of the presentationof a movie, browsable slideshows etc. A playlist is a collection ofplayitems and typically spans the whole length of a presentation. Aplaylist has one main presentation and may have several sub-presentationpaths. For example a video stream with an associated audio and textsubtitle track.

The following sub-path are known in BD systems:

0 reserved1 Main transport stream (TS) for a main-path of Movie2 Main TS for a main-path of Time based slide show3 Main TS for a main-path of Browsable slide show4 Sub TS for a sub-path of Browsable slide show5 Sub TS for a sub-path of Interactive Graphics menu6 Sub TS for a sub-path of Text subtitle7 Sub TS for a sub-path of one or more elementary streams path8 255 reserved

In an embodiment of the invention, an additional information stream thatcontains 3D information is added as a sub-path of the main 2D videostream in the playlist. This may be implemented by means of extendingthe Sub-path types to include a new type indicating that a sub-play itempoints to an elementary stream carrying a 3D video stream that should bepresented together with the main 2D video stream and sent to thedisplay. For example, this extension could be a sub-path type value of8.

With respect to implementation of the invention in a playback device asdescribed with reference to FIG. 2, the following are noted:

According to the invention, the playback device is provided with means(30) for storing a playback setting of a playback device indicatingwhether the video information should be displayed two-dimensional (2D)or three dimensional (3D). For example, such means may be provided as anon-volatile memory provided in the control unit 17 or the outputtingunit 28.

Furthermore, the playback device according to the invention is providedwith means (29) for receiving video information and associated playbackinformation being organized according to a playback format, the videoinformation comprising a primary video stream for two-dimensional (2D)display and an additional information stream for enablingthree-dimensional (3D) display, the associated playback informationcomprising display information indicating the types of video streamspresent with means for processing the display information to determinethat both two-dimensional (2D) display are possible andthree-dimensional (3D) display are possible for the received videoinformation and with means for processing for display of either theprimary video stream or the primary video stream and the additionalinformation stream, in accordance with the stored playback setting ofthe playback device. The means (29) referred hereinabove may correspondto an application (29) that runs as part of the movie presentation inthe control unit 17 and that can query the playback setting and adjustthe presentation accordingly. From the perspective of a user interface,the selection of 2D or 3D playback can be as easy as a dedicated 2D/3Dbutton on the remote control.

Alternatively the playback device can be configured to directly selectthat part of the video information that contains 3D information byidentifying those parts from the stream description in case noapplication is present. This can also be used when the user navigatesthe content directly (for example on a personal computer instead of adedicated video player) in which case the player or system can indicatewhich parts of the content may be presented in 3D.

Furthermore, the outputting unit is further adapted for processing fordisplay either the primary video stream or the primary video stream andthe additional information stream, in accordance with the storedplayback setting of the playback device.

In the initial stage of the introduction, it is expected that contentauthors will experiment with the new medium whereby parts of a videostream will be 3D-video, whilst the main video will still be viewedmostly in 2D or in an enhanced 2D experience, whereby the content is in2D but it is converted real-time in the display from 2D to “3D”. Hence,it is not only desirable to easily switch between 2D and 3D content, butthis switch from 2D to 3D during presentation should take place in a“seamless” manner. The user end will notice that the presentation haschanged, however the transition should be un-obtrusive, not cause blackframes or other artifacts in the video, which would interfere with thepositive experience of the end-user.

When transitioning from 2D to 3D or vice-versa, the playback device andthe video processing stage must be re-configured to change frompresentation mode. During this re-configuration process, black frames orartifacts may appear on screen, which severally disrupt the movieexperience. To avoid this and viewer discomfort at least one of thefollowing issues may be addressed in an improved embodiment of theinvention:

The content itself preferably is suitable to switch between 2D and 3D.This means that the content author ensures that the points where thecontent can be switched between 2D and 3D do not occur in the middle ofa shot or video scene, but instead can only take place at a scene cut,or at the beginning of a new shot. Also the transition should occur inpart of the content and story line for which it makes sense to switch toensure a more immersive experience for example action shots, or in apart of the content where the user can “explore” a scene in more detail.

The strength of the 3D effect should increase gradually, allowing theusers eyes and visual system to adjust and become comfortable with the3D viewing experience.

Preferably, the decoding of the video is not interrupted, hence no blackframes or hiccups in the presentation.

Preferably, The display does not show artifacts when switching from 2Dto 3D mode.

In order to allow the strength of the 3D effect to increase graduallywithout showing artefacts or black frames, a solution according to theinvention is that the playback device and the processing stage in the 3Ddisplay work together to achieve a “seamless” transition. To achievethis, the inventors designed a system that provides an applicationinterface (API) that can indicate exactly when the transition shouldoccur together with the duration of the transition. Suitable knownapplication interfaces to be used as a start point are the Blu-ray Discapplication interfaces (HD-Movie mode or BD-Java). According to anembodiment of the invention, in response to a command to execute atransition from 2D to 3D or vice-versa, the application at the playbackdevice embeds commands in a frame header (or on the interface directly)to make the display change the depth settings in the display and, ifsupported by the display, also commands to control the number of views.Additionally the playback device selects an appropriate section ofcontent on the optical disc for playback during the transition period,followed by starting playback of 3D video content.

Hence further embodiments of the invention relates to at least one or toany combination of the following:

An application interface (API) enabled to allow an application on theoptical disc to indicate when to transition between 2D and 3D mode andwhat a desired transition period is.

Commands embedded in a frame header or directly on the video interface(HDMI) to indicate to the 3D display to change the depth- and optionalview settings. Alternatively commands embedded in a frame header or onthe video interface, which indicate to the display to transition between2D and 3D, and preferably the duration of the transition.

A format of video content on the optical disc which is authored suchthat the “depth” data is interleaved with black lines to create a framesize and resolution that matches the 2D image content and which providesa seamless experience from a content perspective between the 2D and 3Dsections of the movie.

A method of combining the 2D image data with the “depth” data thatavoids re-configuration of the hard- and software in the playbackdevice.

As mentioned before one of the problems to overcome for obtaining aseamless transition is that the depth effect should change gradually.Herein we disclose two solutions according to the invention.

In a first solution, the playback device can alter the colors of thedepth map such that the depth increases and decreases gradually, whilein the second solution either the playback device or the 3D display areenabled to change settings in the rendering unit. The rendering unitgenerates multiple views for display on the multi-view display byshifting pixels from the 2D image to the left or right to create a newview. The amount of shift depends on the value of the correspondingpixel in the depth or disparity map (there is a approximated linearrelation between disparity and depth) and on the offset and gainsettings in this stage. By manipulating the gain values the amount ofdepth can be increased (in fact this increases the amount of pixelshift), the offset can be used to position the depth of more behindor—in front of the screen. To gradually change the depth for a smoothtransition the player could change these gain and offset parameters inthe rendering unit and in this way change the perceived depth withouthaving to alter the content of the depth or disparity map stream.

In a known autostereoscopic display these parameters can be set by theuser through a control panel. FIG. 4 illustrates how these parameterscan be changed over time such that a display changes the apparentposition of a displayed object.

On vertical axis the relative gain and the depth are displayed, while onthe horizontal axis time is displayed. At moment t1 a change from 2D to3D is initiated, as a result of the user changing the display mode, orby the player automatically when a transition between 2D and 3D isdetected, or by a Java application on disc through a special API. Thislast approach requires the definition of a new API for the playbackapparatus, to be described later in this application, but it has theadvantage that it gives content authors dynamic control of thesesettings.

The change of parameter takes place over a finite time interval, to afinal desired value, when the display functions in 3D mode. Between timemoments t3 and t4 a change from 3D to 2D is illustrated. As can be seenfrom FIG. 4 the gain value varies between 0 and 63, with 63 being themaximum amount of “depth”. The offset may vary from 0 to 255, with 128being on the screen and 0 behind and 255 in front

In case of BD media and BD players, it is known that such systems makeuse of Java and, in particular, the org.bluray.media package. A suitableAPI, would be part of the org.bluray.media package and would inherit themethods from the javax.media.Control class as detailed below:

Class 3DvideoOffsetControl

void setOffset(int offset)int getOffset( )

Class 3DvideoGainControl

void setGain(int gain)int getGain( )

Furthermore, in an improved embodiment, suitable interfaces such that anapplication can register to an event to indicate any changes to thesesettings are provide.

It is known that typical autostereoscopic displays sacrifice someresolution when displaying in 3D mode. This is because showing multipleviews requires additional pixels, the higher the number of views themore pixels that are required and thus the lower the resolution.According to an embodiment of the invention, one solution to increasethe resolution in normal 2D mode is the use of a switchable display thatcan switch on and off the sheet of lenticular lenses in front of thedisplay. This switching does take some time (seconds) but it isnon-disturbing to the user. According to another embodiment of theinvention, a system is added to enable the rendering unit to graduallyincrease or -decrease the number of views and thereby at the same timegradually changing the resolution. This system may coupled to theswitching on and-off of the lenticular lenses.

It is known that current state-of-the art autostereoscopic displays havethe rendering unit integrated and use commands embedded in a header tochange rendering parameters. Alternatively, according to an embodimentof the invention, the playback apparatus is enabled to transmitcorresponding rendering parameters to the rendering unit provided in the3D display over the DVI\HDMI bus using the known i2c protocol.

Hence, according to the invention, the known rendering parameter set isextended to include additional parameters for setting the number ofviews. These additional parameter to the known ones, may be disparityand offset parameters that can be used by the player to ensure a“seamless” transition from 2D to 3D and vice versa.

In an alternative embodiment, the seamless transition is controlled bythe rendering unit itself. In this case the additional parametercorresponds to a command from the playback device to the rendering unitin the display to gradually switch from 2D to 3D, possibly with anadditional timing parameter to indicate the time within which thetransition should occur, such that to align the transition with thecontent. Preferably these parameters are standardized such that a Javaapplication on the disc written by a content author can controltransition parameter on all playback apparatuses. The alternativeembodiment may be more advantageous as the transition between switchingbetween the lenses on or off can then be tightly controlled by thedisplay.

The suitable application interface (API) in case of BD systems forsupporting seamless transitions from 2D to 3D in switch-able displayscould be defined as follows:

Class DisplayMode

setTo3D(int dtime, long framenumber)setTo2D(int dtime, long framenumber).wherein dtime=duration of transition (in time units or number of frames)framenumber=the frame at which the display should start the transition.

Next to defining the API as described above, the transition parametersneed to be communicated to the display. The transition parameterspreferably comprises a transition time parameter and a commandindicating the mode switch should be embedded in a header of the frameindicated by the frame number of the API method. Alternatively, insteadof a header, the transition parameters may be sent using i2c commands asknown from the Enhanced Display Data Channel Standard, Version 1 (1999)VESA, which is available at www.vesa.org. Other commands as known fromthe 2D video format specification for HDMI or the DisplayPort Standardv1.1 Mar. 2007 VESA, which is available at www.vesa.org, may also beused.

The duration transition parameter is advantageous in order to allowalignment the transition between modes with the video content on disc.In order to provide a seamless natural experience, preferably the videocontent is authored such that that the boundaries of a transition arebetween scenes and not in the middle of a scene. Additionally, in orderto provide an optimal experience, the disc may contain a section ofcontent authored such that the transition occurs naturally withoutinterrupting the movie experience. This implies that the disparity (thedepth effect) increases gradually and movement in the scenes is minimalduring the transition segment. Preferably, other depth cues (such aslinear perspective, occlusion, lighting) are only sparsely used beforeand during the transition and they match the depth impression from thedisparity created by the 3D part of the content.

In addition to providing a gradual transition, it is also desirable thatno artifacts or black frames occur, as this may interrupt the movieexperience. To achieve this several steps can be taken.

First of all, when the playback is switched between 2D and 3D, it ispreferable that the buffers for decoding of all the streams do notunder-or overflow. The decoding must be continuous. In Blu-ray Discsystems the conditions a 2D stream must meet with regard to videoparameters and allocation on the disc were defined. For example, for aseamless connection between segments of video, the resolution and framerate etc should be the same between the segments. Also the segmentsshould be allocated on the disc such that during reading, the decodingbuffers do not go empty (causing black frames). For “depth” based orstereo formats as previously described, the same rules may apply as tothe 2D case. These formats mean that in a writing device, additionalstreams are multiplexed in the transport stream, and in a reading devicethe additional streams are decoded and presented simultaneously. 3Dstreams using the auxiliary stream carriage method were defined in MPEGISO/IEC JTC1/SC29/WG11; WD 1.0 of ISO/IEC 23002-3 Auxiliary Video Data.Hence such an additional stream, in case of BD systems, willautomatically meet the same requirements with regards to bitrate andallocation on disc as those known for 2D streams.

Some additional considerations must be taken into account. In anembodiment of the invention, additional 3D information was carried as asecondary video stream in BD, and this additional 3D information couldbe presented in a Picture-in-Picture (PIP) stream. Experiments performedby the inventors have shown that this solution according to theinvention works, activating the PIP feature may induce some delay.Inventors found that the origin of the delay is related to thereconfiguration of the system such that the secondary and/or the primaryvideo are scaled. During this re-configuration process the system mayshow artifacts such as black frames or garbled images. To overcome thisproblem, the inventor came up with an improved embodiment of theinvention, which uses interleaving of the primary video with thesecondary video and which further uses luma keying. FIG. 3 shows anexample of how this embodiment of the invention works. It is noted thatin FIG. 3 the lines of the depth map data are larger and they have beenexaggerated compared to reality, such that the effect are visible in theimage.

FIG. 5A is a depth map image with some additional information (the grayarea) to carry background or occlusion data is shown. In reality theamount of additional information can be much smaller. The resolution ofthe “depth” data may be less than a quarter of the 2D resolution, oreven lower in an improved embodiment wherein technologies like CADE, asdisclosed in WO200213141 to be incorporated herein by reference, areused. In FIG. 5B the “depth” data is interleaved with black lines insuch a way that the total size of the “depth” map data is the same asthat of the 2D video. This may be done in a playback device but morelikely it could be provided in this format on the disc. In this form the“depth” data, interleaved with black lines, is overlaid on top of the 2Dvideo. Then, luma keying is performed to make the black linestransparent, hence revealing most parts of the 2D video in thebackground. This is depicted in FIG. 5D.

As is shown in FIGS. 5A, 5B, 5C and 5D, some parts of the 2D video willbe covered by the “depth” data. However as the resolution of the depthdata may be small, this loss in vertical resolution will be quite small.Also the interleaving with black lines may be done in such a way thatmostly the lines at the top and the bottom of the 2D video backgroundare covered. When used for an autostereoscopic display, this is evenless of an issue as the display in 3D mode cannot show with the full HDresolution, as generating the required additional views comes at thecost of display resolution.

According to this embodiment of the invention, the associated Blu-rayDisc playlist is configured such that the secondary video stream istreated as a picture-in-picture stream, and that luma keying is to beapplied and, preferably, the upper_limit_luma_key value is set to zero.

Alternatively, an additional entry is added to the extension data asused in BD system, the additional entry defined for 3D video streamsallowing PIP metadata or 3D metadata. The syntax of both the 3D PIPmetadata and 3D metadata can be the same exact for some namingconventions. For both 3D and PIP all the entries are required.

Finally it is noted that exemplary embodiments of the inventionhereinabove were described with reference to a playback device forplayback of information from an optical disc. It is noted that thesource of the information is irrelevant, it may be provided locally on arecorded media such as optical media, hard disc or solid state memory,or it can be received with broadcasting via wired or wirelesstransmission systems, including the internet. The invention may beimplemented in any device for playback of video information, including,among others, hard-disc recorders, set top boxes (STB) and digital(satellite/terrestrial/cable) receivers.

This invention can be summarized as follows: The invention relates to asignal comprising video information and associated playback information,the video information and associated playback information beingorganized according to a playback format, the video informationcomprising a primary video stream for two-dimensional (2D) display, andan additional information stream for enabling three-dimensional (3D)display, wherein that the associated playback information comprisesdisplay information indicating the types of display possible. Theinvention also relates to a method and device for playback of such asignal, the method comprising receiving the video information and theassociated playback information, processing the display information todetermine that both two-dimensional (2D) display possible andthree-dimensional (3D) display are possible for the received videoinformation; determining a playback setting of a playback deviceindicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D); and processing fordisplay either the primary video stream or the primary video stream andthe additional information stream, in accordance with the playbacksetting of the playback device.

It should be noted that the above-mentioned embodiments are meant toillustrate rather than limit the invention. And that those skilled inthe art will be able to design many alternative embodiments withoutdeparting from the scope of the appended claims. In the claims, anyreference signs placed between parentheses shall not be construed aslimiting the claim. Use of the verbs “comprise” and “include” and theirconjugations do not exclude the presence of elements or steps other thanthose stated in a claim. The article “a” or an” preceding an elementdoes not exclude the presence of a plurality of such elements. Theinvention may be implemented by means of hardware comprising severaldistinct elements and by means of a suitable programmed computer. Acomputer program may be stored/distributed on a suitable medium, such asoptical storage or supplied together with hardware parts, but may alsobe distributed in other forms, such as being distributed via theInternet or wired or wireless telecommunication systems. In asystem/device/apparatus claim enumerating several means, several ofthese means may be embodied by one and the same item of hardware orsoftware. The mere fact that certain measures are recited in mutuallydifferent dependent claims does not indicate that a combination of thesemeasures cannot be used to advantage.

1. A method of playback of video information suitable for bothtwo-dimensional (2D) display and three-dimensional (3D) display, themethod comprising: receiving video information and associated playbackinformation, wherein the video information and associated playbackinformation are organized according to a playback format, the videoinformation comprising a primary video stream for two-dimensional (2D)display and at least at times comprising an additional stream forenabling three-dimensional (3D) display when processed together with theprimary video stream, the associated playback information comprisingdisplay information indicating the types of video streams present, andcomprising one or more playlists, the playlists indicating a sequence ofitems to be played back; processing the display information to determinewhether two-dimensional (2D) display is possible and whetherthree-dimensional (3D) display is possible for the received videoinformation; determining a playback setting of a playback deviceindicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D); and either processingfor display as two-dimensional (2D) the primary video stream without theadditional stream or otherwise processing together for display asthree-dimensional (3D) the primary video stream with the additionalstream, in accordance with the associated playback information and inaccordance with the playback setting of the playback device, thethree-dimensional (3D) display being enabled by an indication in aplaylist of the one or more playlists that the additional stream is anauxiliary presentation path configured as a sub-path of the primaryvideo stream.
 2. The method of claim 1, further comprising: receiving arequest to switch the playback setting from two-dimensional (2D) displayto three-dimensional (3D) display or from three-dimensional (3D) displayto two-dimensional (3D) display; and when two-dimensional (2D) displayand three-dimensional (3D) display are both possible, switching in aseamless manner from two-dimensional (2D) display to three-dimensional(3D) display or from three-dimensional (3D) display to two-dimensional(2D) display.
 3. The method of claim 2, further comprising performingthe switching from two-dimensional (2D) display to three-dimensional(3D) display or from three-dimensional (3D) display to two-dimensional(3D) display at predefined moments during playback.
 4. The method ofclaim 1, wherein: the primary video stream comprises video items, theadditional stream comprises information items, the associated playbackinformation comprising playlists, each playlist indicating a sequence ofitems to be played back, at least one playlist comprising a mainpresentation path indicating a main sequence of video items of theprimary video stream to be played back and at least at times anauxiliary presentation path indicating an auxiliary sequence to beplayed back, and the auxiliary sequence comprising video items from theprimary video stream and corresponding information items from theadditional stream.
 5. The method of claim 1, wherein: the playbackformat substantially corresponds to DVD-Video playback format, theplayback information comprising Video Title Set Information (VTSI)comprising Video Attribute information, and the Video Attributeinformation comprising a video attribute indicating that thecorresponding Video Title Set Information (VTSI) comprises theadditional stream for enabling three-dimensional (3D) display.
 6. Aplayback device for playback of video information suitable for bothtwo-dimensional (2D) display and three-dimensional (3D) display, thedevice comprising: a receiver to receive video information andassociated playback information which are both organized according to aplayback format, the video information comprising a primary video streamfor two-dimensional (2D) display and at least at times an additionalstream for enabling three-dimensional (3D) display, the associatedplayback information comprising display information indicating the typesof video streams present and comprising one or more playlists, theplaylists indicating a sequence of items to be played back; a processorto process the display information to determine whether two-dimensional(2D) display is possible and whether three-dimensional (3D) display ispossible for the received video information; a memory to store aplayback setting of a playback device indicating whether the videoinformation should be displayed two-dimensional (2D) or threedimensional (3D); said processor either processing for displaying astwo-dimensional (2D) the primary video stream without the additionalstream or otherwise processing together for displaying asthree-dimensional (3D) the primary video stream with the additionalstream, in accordance with the associated playback information, and inaccordance with the stored playback setting of the playback device, thethree-dimensional (3D) display being enabled by an indication in aplaylist of the one or more playlists that the additional stream is anauxiliary path configured as a sub-path of the primary video stream. 7.The device of claim 6, wherein the primary video stream comprises videoitems, the additional stream comprises information items, the associatedplayback information comprises playlists, each playlist indicating asequence of items to be played back, at least one playlist comprising amain presentation path indicating a main sequence of video items of theprimary video stream to be played back and at least at times anauxiliary presentation path indicating an auxiliary sequence to beplayed back, the auxiliary sequence comprising video items from theprimary video stream and corresponding information items from theadditional stream.
 8. The device of claim 7, wherein the playback formatcorresponds to Blu-ray playback format.
 9. The device of claim 6,wherein the playback format corresponds to DVD-Video playback format,the playback information comprising Video Title Set Information (VTSI)comprising Video Attribute information, the Video Attribute informationcomprising a video attribute indicating that the corresponding VideoTitle Set Information (VTSI) comprises the additional stream forenabling three-dimensional (3D) display.
 10. The device of claim 6,wherein the primary video stream and the additional stream are MPEGelementary streams multiplexed together in a multiplexed stream, and theadditional stream is an MPEG auxiliary stream.
 11. The device of claim6, wherein the playback setting of the playback device is controllablebased on user input.
 12. The device of claim 6, wherein playback settingof the playback device is stored in a register.
 13. A non-transitorycomputer readable media encoded with video information and associatedplayback information, and when introduced to a playback device, theplayback information controlling a processor of the playback device toperform the acts of: receiving the video information and associatedplayback information from the medium, the video information andassociated playback information being organized according to a playbackformat, the video information comprising a primary video stream fortwo-dimensional (2D) display, and at least at times an additional streamfor enabling three-dimensional (3D) display when processed together withthe primary video stream, the associated playback information comprisingdisplay information indicating the types of video streams present, andcomprising one or more playlists, the playlists indicating a sequence ofitems to be played back; processing the display information to determinewhether two-dimensional (2D) display is possible and whetherthree-dimensional (3D) display is possible for the received videoinformation; determining a playback setting of a playback deviceindicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D); and either processing todisplay as two-dimensional (2D) the primary video stream without theadditional stream or otherwise processing together to display asthree-dimensional (3D) the primary video stream with the additionalstream, in accordance with the associated playback information, and inaccordance with the playback setting of the playback device, thethree-dimensional (3D) display being enabled by an indication in aplaylist of the one or more playlists that the additional stream is anauxiliary path configured as a sub-path of the primary video stream. 14.The medium of claim 13, wherein the primary stream comprises videoitems, the additional stream comprises information items, the associatedplayback information comprising playlists, each playlist indicating asequence of items to be played back, at least one playlist comprising amain presentation path indicating a main sequence of video items of theprimary video stream to be played back and an auxiliary presentationpath indicating an auxiliary sequence to be played back, the auxiliarysequence comprising video items from the primary video stream andcorresponding information items from the additional stream.
 15. Themedium of claim 14, wherein the playback format corresponds to Blu-rayplayback format.
 16. The medium of claim 13, wherein the playback formatcorresponds to DVD-Video playback format, the playback informationcomprising Video Title Set Information (VTSI) comprising Video Attributeinformation, the Video Attribute information comprising a videoattribute indicating that the corresponding Video Title Set Information(VTSI) comprises the additional stream for enabling three-dimensional(3D) display.
 17. The medium of claim 13, wherein the primary videostream and the additional stream are MPEG elementary streams multiplexedtogether in a multiplexed stream, and the additional stream is an MPEGauxiliary stream.
 18. A method of playback of video information suitablefor both two-dimensional (2D) display and three-dimensional (3D)display, the method comprising: receiving video information andassociated playback information, wherein the video information andassociated playback information are organized according to a playbackformat, the video information comprising a primary video stream fortwo-dimensional (2D) display and at least at times an additional streamfor enabling three-dimensional (3D) display, the associated playbackinformation comprising display information indicating the types of videostreams present; processing the display information to determine whethertwo-dimensional (2D) display is possible and whether three-dimensional(3D) display is possible for the received video information; determininga playback setting of a playback device indicating whether the videoinformation should be displayed two-dimensional (2D) or threedimensional (3D); processing for display as two-dimensional (2D) theprimary video stream without the additional stream or otherwiseprocessing together for display as three-dimensional (3D) the primaryvideo stream with the additional stream, in accordance with the playbackinformation, and in accordance with the playback setting of the playbackdevice, wherein the primary stream comprises video items, the additionalstream comprises information items, the associated playback informationcomprising playlists, each playlist indicating a sequence of items to beplayed back, at least one playlist comprising a main presentation pathindicating a main sequence of video items of the primary video stream tobe played back and an auxiliary presentation path indicating anauxiliary sequence to be played back, the auxiliary sequence comprisingvideo items from the primary video stream and corresponding informationitems from the additional stream.
 19. The method of claim 18 wherein asub-play item points to a elementary stream carrying a 3D video streamthat should be presented together with the main 2D video stream and sentto the display.
 20. The method of claims 18, further comprising:receiving a request to switch the playback setting from two-dimensional(2D) display to three-dimensional (3D) display or from three-dimensional(3D) display to two-dimensional (3D) display; and when two-dimensional(2D) display and three-dimensional (3D) display are both possible,switching in a seamless manner between from two-dimensional (2D) displayto three-dimensional (3D) display or from three-dimensional (3D) displayto two-dimensional (3D) display.
 21. A playback device for playback ofvideo information suitable for both two-dimensional (2D) display andthree-dimensional (3D) display, the device comprising: a receiver forreceiving video information and associated playback information whichare both organized according to a playback format, the video informationcomprising a primary video stream for two-dimensional (2D) display andat least at times an additional stream for enabling three-dimensional(3D) display, the associated playback information comprising displayinformation indicating the types of video streams present; a processorfor processing the display information to determine whethertwo-dimensional (2D) display is possible and whether three-dimensional(3D) display is possible for the received video information; memory forstoring a playback setting of a playback device indicating whether thevideo information should be displayed two-dimensional (2D) or threedimensional (3D); said processor for either processing to display astwo-dimensional (2D) the primary video stream without the additionalstream or otherwise processing together to display as three-dimensional(3D) the primary video stream with the additional stream, in accordancewith the playback information, and in accordance with the storedplayback setting of the playback device, wherein the primary streamcomprises video items, the additional stream comprises informationitems, the associated playback information comprises playlists, eachplaylist indicating a sequence of items to be played back, wherein atleast one playlist comprising a main presentation path indicating a mainsequence of video items of the primary video stream to be played backand an auxiliary presentation path indicating an auxiliary sequence tobe played back, the auxiliary sequence comprising video items from theprimary video stream and corresponding information items from theadditional stream.
 22. The device of claim 21, wherein a sub-play itempoints to an elementary stream carrying a 3D video stream that should bepresented together with the main 2D video stream and sent to thedisplay.
 23. The device of claim 21, wherein the playback formatcorresponds to Blu-ray playback format.
 24. The device of claim 21,wherein the primary video stream and the additional stream are MPEGelementary streams multiplexed together in a multiplexed stream, and theadditional stream is an MPEG auxiliary stream.
 25. The device of claim21, wherein the playback setting of the playback device is controllablebased on user input.
 26. The device of claim 21, wherein a playbacksetting of the playback device is stored in a register.
 27. Anon-transitory computer readable medium encoded with video informationand associated playback information, and when introduced to a playbackdevice, the playback information controlling a processor of a playbackdevice to perform the acts of: receiving the video information andassociated playback information from the medium, the video informationand associated playback information being organized according to aplayback format, the video information comprising a primary video streamfor two-dimensional (2D) display, and at least at times an additionalstream for enabling three-dimensional (3D) display when processedtogether with the primary video stream, the associated playbackinformation comprising display information indicating the types of videostreams present, processing the display information to determine whethertwo-dimensional (2D) display is possible and whether three-dimensional(3D) display is possible for the received video information; determininga playback setting of a playback device indicating whether the videoinformation should be displayed two-dimensional (2D) or threedimensional (3D); and either processing to display as two-dimensional(2D) the primary video stream without the additional stream or otherwiseprocessing together to display as three-dimensional (3D) the primaryvideo stream with the additional stream, in accordance with the playbackinformation, and in accordance with the playback setting of the playbackdevice; and wherein the primary video stream comprises video items, theadditional stream comprises information items, the associated playbackinformation comprises playlists, each playlist indicating a sequence ofitems to be played back, wherein at least at times at least one playlistcomprising a main presentation path indicating a main sequence of videoitems of the primary video stream to be played back and an auxiliarypresentation path indicating an auxiliary sequence to be played back,the auxiliary sequence comprising video items from the primary videostream and corresponding information items from the additional stream.28. The medium of claim 27, wherein a sub-play item points to aelementary stream carrying a 3D video stream that should be presentedtogether with the main 2D video stream and sent to the display.
 29. Themedium of claim 27, wherein the playback format corresponds to Blu-rayplayback format.
 30. The medium of claim 27, wherein the playback formatcorresponds to DVD-Video playback format, the playback informationcomprising Video Title Set Information (VTSI) comprising Video Attributeinformation, the Video Attribute information comprising a videoattribute indicating that the corresponding Video Title Set Information(VTSI) comprises the additional stream for enabling three-dimensional(3D) display.
 31. The medium of claim 27, wherein the primary videostream and the additional stream are MPEG elementary streams multiplexedtogether in a multiplexed stream, and the additional stream is an MPEGauxiliary stream.
 32. A method of playback of video information suitablefor both two-dimensional (2D) display and three-dimensional (3D)display, the method comprising: receiving video information andassociated playback information, wherein the video information andassociated playback information are organized according to a playbackformat, the video information comprising a primary video stream fortwo-dimensional (2D) display and at least at times an additional streamfor enabling three-dimensional (3D) display when processed together withthe primary video stream, the associated playback information comprisingdisplay information indicating the types of video streams present;processing the display information to determine whether two-dimensional(2D) display is possible and whether three-dimensional (3D) display ispossible for the received video information; determining a playbacksetting of a playback device indicating whether the video informationshould be displayed two-dimensional (2D) or three dimensional (3D); andeither processing to display as two-dimensional (2D) the primary videostream without the additional stream or otherwise processing together todisplay as three-dimensional (3D) the primary video stream with theadditional stream, in accordance with the playback information, and inaccordance with the playback setting of the playback device, anddepending on a predetermined bit of the Video Title Set Information inthe additional stream, the bit indicating whether the additional streamcontains three-dimensional (3D) video information.
 33. The method ofclaim 32, further comprising receiving a request to switch the playbacksetting from two-dimensional (2D) display to three-dimensional (3D)display or from three-dimensional (3D) display to two-dimensional (3D)display; when two-dimensional (2D) display and three-dimensional (3D)display are both possible, switching in a seamless manner between fromtwo-dimensional (2D) display to three-dimensional (3D) display or fromthree-dimensional (3D) display to two-dimensional (3D) display dependingon the request.
 34. The method of claim 33, further comprisingperforming the switching from two-dimensional (2D) display tothree-dimensional (3D) display or from three-dimensional (3D) display totwo-dimensional (3D) display at predefined moments during playback. 35.The method of claim 32 wherein the primary video stream comprises videoitems, the additional stream comprises information items, the associatedplayback information comprising playlists, each playlist indicating asequence of items to be played back, at least one playlist comprising amain presentation path indicating a main sequence of video items of theprimary video stream to be played back and an auxiliary presentationpath indicating an auxiliary sequence to be played back, the auxiliarysequence comprising video items from the primary video stream andcorresponding information items from the additional stream.
 36. Themethod of claim 32, wherein the playback format substantiallycorresponds to DVD-Video playback format, the playback informationcomprising Video Title Set Information (VTSI) comprising Video Attributeinformation, the Video Attribute information comprising a videoattribute indicating that the corresponding Video Title Set Information(VTSI) comprises the additional stream for enabling three-dimensional(3D) display.
 37. The media of claim 32, wherein the predetermined bitof the Video Title Set Information is a bit in the Video Attribute Entryof the Video Title Set Information Management Table of the Video TitleSet Information.
 38. A playback device for playback of video informationsuitable for both two-dimensional (2D) display and three-dimensional(3D) display, the device comprising a receiver to receive videoinformation and associated playback information which are both organizedaccording to a playback format, the video information comprising aprimary video stream for two-dimensional (2D) display and at least attimes an additional stream for enabling three-dimensional (3D) display,the associated playback information comprising display informationindicating the types of video streams present; a processor to processthe display information to determine whether two-dimensional (2D)display is possible and whether three-dimensional (3D) display ispossible for the received video information; a memory to store aplayback setting of a playback device indicating whether the videoinformation should be displayed two-dimensional (2D) or threedimensional (3D); said processor either processing to display astwo-dimensional (2D) the primary video stream without the additionalstream or otherwise processing together to display as three-dimensional(3D the primary video stream with the additional stream, in accordancewith the playback information, and in accordance with the storedplayback setting of the playback device, and depending on apredetermined bit of the Video Title Set Information in the additionalstream, the bit indicating whether the additional stream containsthree-dimensional (3D) video information.
 39. The device of claim 38,wherein the primary stream comprises video items, the additional streamcomprises information items, the associated playback informationcomprises playlists, each playlist indicating a sequence of items to beplayed back, at least one playlist comprising a main presentation pathindicating a main sequence of video items of the primary video stream tobe played back and an auxiliary presentation path indicating anauxiliary sequence to be played back, the auxiliary sequence comprisingvideo items from the primary video stream and corresponding informationitems from the additional stream.
 40. The device of claim 38, whereinthe playback format corresponds to Blu-ray playback format.
 41. Thedevice of claim 38, wherein the playback format corresponds to DVD-Videoplayback format, the playback information comprising Video Title SetInformation (VTS) comprising Video Attribute information, the VideoAttribute information comprising a video attribute indicating that thecorresponding Video Title Information (VTSI) comprises the additionalstream for enabling three-dimensional (3D) display.
 42. The device ofclaim 38, wherein the primary video stream and the additional stream areMPEG elementary streams multiplexed together in a multiplexed stream,and the additional stream is an MPEG auxiliary stream.
 43. The device ofclaim 38, wherein the playback setting of the playback device iscontrollable based on user input.
 44. The device of claim 38, whereinplayback setting of the playback device is stored in a register of theplayback device.
 45. The media of claim 39, wherein the predeterminedbit of the Video Title Set Information is a bit in the Video AttributeEntry of the Video Title Set Information Management Table of the VideoTitle Set Information.
 46. A non-transitory computer-readable mediumencoded with video information and associated playback information, andwhen introduced to a playback device, the playback informationcontrolling a processor of a playback device to perform the acts of:receiving the video information and associated playback information, thevideo information and associated playback information being organizedaccording to a playback format, the video information comprising aprimary video stream for two-dimensional (2D) display, and at least attimes an additional stream for enabling three-dimensional (3D) displaywhen processed together with the primary video stream, the associatedplayback information comprising display information indicating the typesof video streams present. processing the display information todetermine whether two-dimensional (2D) display is possible and whetherthree-dimensional (3D) display is possible for the received videoinformation; determining a playback setting of a playback deviceindicating whether the video information should be displayedtwo-dimensional (2D) or three dimensional (3D); and either processing todisplay as two-dimensional (2D) the primary video stream without theadditional stream or otherwise processing together to display asthree-dimensional (3D) the primary video stream with the additionalstream, in accordance with the playback information, and in accordancewith the playback setting of the playback device, depending on apredetermined bit of the Video Title Set Information in the additionalstream, the bit indicating whether the additional stream containsthree-dimensional (3D) video information.
 47. The medium of claim 46,wherein the primary stream comprises video items, the additional streamcomprises information items, the associated playback informationcomprising playlists, each playlist indicating a sequence of items to beplayed back, at least one playlist comprising a main presentation pathindicating a main sequence of video items of the primary video stream tobe played back and an auxiliary presentation path indicating anauxiliary sequence to be played back, the auxiliary sequence comprisingvideo items from the primary video stream and corresponding informationitems from the additional stream.
 48. The medium of claim 47, whereinthe playback format corresponds to Blu-ray playback format.
 49. Themedium of claim 46, wherein the playback format corresponds to DVD-Videoplayback format, the playback information comprising Video Title SetInformation (VTSI) comprising Video Attribute information, the VideoAttribute information comprising a video attribute indicating that thecorresponding Video Title Set Information (VTSI) comprises theadditional stream for enabling three-dimensional (3D) display.
 50. Themedium of claim 46, wherein the primary video stream and the additionalstream are MPEG elementary streams multiplexed together in a multiplexedvideo streamand the additional stream is an MPEG auxiliary stream. 51.The media of claim 46, wherein the predetermined bit of the Video TitleSet Information is a bit in the Video Attribute Entry of the Video TitleSet Information Management Table of the Video Title Set Information. 52.A transmitting device for transmitting video information suitable forboth two-dimensional (2D) display and three-dimensional (3D) display,the device comprising: a receiver to receive video informationcomprising a primary video stream for two-dimensional (2D) display andcomprising at least at times an additional stream for enablingthree-dimensional (3D) display when processed together with the primaryvideo stream, the primary video stream comprises video items, theadditional stream comprises information items, a drive to rotate anoptical disc, the optical disc having tracks for writing the videoinformation and associated playback information; a read/write opticalhead comprising an optical system to generate a radiation beam, afocusing actuator to move the focus of the radiation beam along theoptical axis of said beam, and a tracking actuator for fine positioningof the radiation spot in a radial direction on a center of the track,the radial direction being in relation to the disc for readinginformation from the optical disc or writing information to the opticaldisc, optical elements for guiding the radiation beam and focusing theradiation beam to a radiation spot on the track of the optical disc, atrack positioning unit for coarse positioning of the head in a radialdirection on the tracks, the radial direction being in relation to thedisc, and a control unit, to control the elements of the transmittingdevice, the control unit comprising a processor; the processer beingconfigured to process the video information to identify the primaryvideo stream and the additional stream the primary video stream and theadditional stream are MPEG elementary streams, and the additional streamis an MPEG auxiliary stream, the processor also being configured toprocess the video information to provide associated playback informationcomprising display information indicating the types of video streamspresent, and associated playback information comprising playlists, eachplaylist indicating a sequence of items to be played back, at least oneplaylist comprising a main presentation path indicating a main sequenceof video items of the primary video stream to be played back and atleast at times an auxiliary presentation path indicating an auxiliarysequence to be played back, the auxiliary sequence comprising videoitems from the primary video stream and corresponding information itemsfrom the additional stream; the processor also being configured to set apredetermined bit in the Video Attribute Entry of the Video Title SetInformation Management Table of the Video Title Set Information in theadditional stream, the bit indicating whether the additional streamcontains three-dimensional (3D) video information; the processor alsobeing configured to process the associated playback information toindicate in a playlist that the additional stream is a sub-path of theprimary video stream; a multiplexer for multiplexing the primary videostream and the additional stream together to form a multiplexed stream;the processor also being configured to organize the video informationand associated playback information according to a playback format; atransmitter to transmit the multiplexed stream together with theassociated playback information in the playback format via the opticaldisc.
 53. A method of transmitting video information suitable for bothtwo-dimensional (2D) display and three-dimensional (3D) display, themethod comprising: receiving video information comprising a primaryvideo stream for two-dimensional (2D) display and comprising at least attimes an additional stream for enabling three-dimensional (3D) displaywhen processed together with the primary video stream, the primary videostream comprises video items, the additional stream comprisesinformation items, rotating an optical disc for scanning the disc, theoptical disc having tracks for writing the video information andassociated playback information; generating a radiation beam, moving thefocus of the radiation beam along the optical axis of said beam, andfine positioning of a radiation spot in a radial direction on a centerof the track, the radial direction being in relation to the disc,guiding the radiation beam and focusing the radiation beam to form theradiation spot on the track of the optical disc, coarse positioningradiation spot in the radial direction on the track, and controlling theelements of a transmitting device; providing associated playbackinformation comprising display information indicating the types of videostreams present, the associated playback information comprisingplaylists, each playlist indicating a sequence of items to be playedback, at least one playlist comprising a main presentation pathindicating a main sequence of video items of the primary video stream tobe played back and at least at times an auxiliary presentation pathindicating an auxiliary sequence to be played back, and the auxiliarysequence comprising video items from the primary video stream andcorresponding information items from the additional stream; processingthe video information to identify the primary video stream and theadditional stream, the primary video stream and the additional streamare MPEG elementary streams, and the additional stream is an MPEGauxiliary stream, setting a predetermined bit in the Video AttributeEntry of the Video Title Set Information Management Table of the VideoTitle Set Information in the additional stream, the bit indicatingwhether the additional stream contains three-dimensional (3D) videoinformation; processing the associated playback information to indicatein a playlist that the additional stream is a sub-path of the primaryvideo stream; multiplexing the primary video stream and the additionalstream together to form a multiplexed stream; organizing the videoinformation and associated playback information according to a playbackformat; transmitting the multiplexed stream together with the associatedplayback information in the playback format via the optical disc.
 54. Anon-transitory computer-readable medium encoded with instructions andwhen introduced to a transmission device suitable for transmission ofboth two-dimensional (2D) and three-dimensional (3D) data, theinstructions controlling at least one processor of the transmissiondevice to perform the acts of: receiving video information comprising aprimary video stream for two-dimensional (2D) display and comprising atleast at times an additional stream for enabling three-dimensional (3D)display when processed together with the primary video stream, theprimary video stream comprises video items, and the additional streamcomprises information items, providing associated playback informationcomprising display information indicating the types of video streamspresent, the associated playback information comprising playlists, eachplaylist indicating a sequence of items to be played back, at least oneplaylist comprising a main presentation path indicating a main sequenceof video items of the primary video stream to be played back and atleast at times an auxiliary presentation path indicating an auxiliarysequence of video items to be played back, and the auxiliary sequencecomprising video items from the primary video stream and correspondinginformation items from the additional stream; processing the videoinformation to identify the primary video stream and the additionalstream, the primary video stream and the additional stream are MPEGelementary streams, and the additional stream is an MPEG auxiliarystream, setting a predetermined bit of the in the Video Attribute Entryof the Video Title Set Information Management Table of the Video TitleSet Information in the additional stream, the bit indicating whether theadditional stream contains three-dimensional (3D) video information;processing the associated playback information to indicate in a playlistthat the additional stream is a sub-path of the primary video stream;multiplexing the primary video stream and the additional stream togetherto form a multiplexed stream; organizing the video information andassociated playback information according to a playback format;transmitting the multiplexed stream together with the associatedplayback information in the playback format.
 55. The media of claim 54wherein, the media is an optical disc that can be read by an opticaldisc writer to program the optical disc writer to write optical discswith video information and associated playback information suitable forboth two-dimensional (2D) display and at least at timesthree-dimensional (3D) display, the instructions further controlling theat least one processor of the transmission device to perform the actsof: rotating an optical disc by controlling a disc drive for scanningthe disc, the optical disc having tracks for writing the videoinformation and associated playback information; generating a radiationbeam by controlling a laser diode, the radiation beam transmitting asignal from the disc to a detector and received by the processor forreading data from the disc, and the radiation beam being controlled bythe processor for writing data to the disc, moving the focus of theradiation beam along the optical axis of said beam by controlling afocusing actuator, and fine positioning of a radiation spot in a radialdirection on a center of the track by controlling a tracking actuator,the radial direction being in relation to the disc, and coarsepositioning the radiation spot in the radial direction on the tracks bycontrolling a track positioning unit.